Properly access mu-mailer and mu-message values.

@@ -812,7 +812,10 @@ SCM_DEFINE (mu_message_send, "mu-message-send", 1, 3, 0,
       mailer_name = SCM_STRING_CHARS (MAILER);
     }
   else
-    mailer_name = SCM_STRING_CHARS(_mu_scm_mailer);
+    {
+      SCM val = MU_SCM_SYMBOL_VALUE("mu-mailer");
+      mailer_name = SCM_STRING_CHARS(val);
+    }
   
   if (!SCM_UNBNDP (FROM) && FROM != SCM_BOOL_F)
     {
@@ -833,7 +836,7 @@ SCM_DEFINE (mu_message_send, "mu-message-send", 1, 3, 0,
       return SCM_BOOL_F;
     }
 
-  if (SCM_INUM(_mu_scm_debug))
+  if (SCM_INUM(MU_SCM_SYMBOL_VALUE("mu-debug")))
     {
       mu_debug_t debug = NULL;
       mailer_get_debug (mailer, &debug);